A hook device for hooking a baggage is provided on an interior wall surface inside a car room. Patent Document 1 discloses a hanger mounting structure including a hook portion. The hanger mounting structure includes a female member including plural engagement leg pieces that hang from a flange portion, and a male member including a shaft portion on the back side of a hook. The engagement leg pieces of the female member are inserted into a mounting hole, and the shaft portion of the male member is pushed into a central hole of the female member, whereby the plural engagement leg pieces are expanded to latch onto the back rim of the mounting hole.